Place potatoes in a large saucepan. Add enough water to cover potatoes. Bring to a boil. Cook 5 to 8 minutes or just until potatoes are fork tender. Drain; rinse with cold water until cool. In a large bowl, combine potatoes, eggs and green onions. In a small mixing bowl, combine mayonnaise, milk, dill weed, salt, pepper, vinegar and mustard. Mix well with a wire whisk. Add mayonnaise mixture to potatoes. Mix gently. Refrigerate 1 hour to blend flavors